University of Oulu

Hänninen, NE, Nykänen, O, Prakash, M, Hanni, M, Nieminen, MT, Nissi, MJ. Orientation anisotropy of quantitative MRI parameters in degenerated human articular cartilage. J Orthop Res. 2021; 39: 861– 870.

Orientation anisotropy of quantitative MRI parameters in degenerated human articular cartilage

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Author: Hänninen, Nina Elina1,2; Nykänen, Olli2; Prakash, Mithilesh2,3;
Organizations: 1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
2Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
3A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
4Medical Research Center Oulu, Oulu University Hospital, University of Oulu, Oulu, Finland
5Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2.3 MB)
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Language: English
Published: John Wiley & Sons, 2020
Publish Date: 2021-05-03


Quantitative magnetic resonance (MR) relaxation parameters demonstrate varying sensitivity to the orientation of the ordered tissues in the magnetic field. In this study, the orientation dependence of multiple relaxation parameters was assessed in cadaveric human cartilage with varying degree of natural degeneration, and compared with biomechanical testing, histological scoring, and quantitative histology. Twelve patellar cartilage samples were imaged at 9.4 T MRI with multiple relaxation parameters, including T₁, T₂, CW − T₁ₚ, and adiabatic T₁ₚ, at three different orientations with respect to the main magnetic field. Anisotropy of the relaxation parameters was quantified, and the results were compared with the reference measurements and between samples of different histological Osteoarthritis Research Society International (OARSI) grades. T₂ and CW − T₁ₚ at 400 Hz spin‐lock demonstrated the clearest anisotropy patterns. Radial zone anisotropy for T₂ was significantly higher for samples with OARSI grade 2 than for grade 4. The proteoglycan content (measured as optical density) correlated with the radial zone MRI orientation anisotropy for T2 (r = 0.818) and CW − T₁ₚ with 400 Hz spin‐lock (r = 0.650). Orientation anisotropy of MRI parameters altered with progressing cartilage degeneration. This is associated with differences in the integrity of the collagen fiber network, but it also seems to be related to the proteoglycan content of the cartilage. Samples with advanced OA had great variation in all biomechanical and histological properties and exhibited more variation in MRI orientation anisotropy than the less degenerated samples. Understanding the background of relaxation anisotropy on a molecular level would help to develop new MRI contrasts and improve the application of previously established quantitative relaxation contrasts.

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Series: Journal of orthopaedic research
ISSN: 0736-0266
ISSN-E: 1554-527X
ISSN-L: 0736-0266
Volume: 39
Issue: Epub ahead of print
Pages: 861 - 870
DOI: 10.1002/jor.24778
Type of Publication: A1 Journal article – refereed
Field of Science: 3126 Surgery, anesthesiology, intensive care, radiology
Funding: Financial support from the Academy of Finland (grants #285909, #293970, #297033, and #319440) and the Orion Research Foundation are gratefully acknowledged.
Academy of Finland Grant Number: 285909
Detailed Information: 285909 (Academy of Finland Funding decision)
297033 (Academy of Finland Funding decision)
319440 (Academy of Finland Funding decision)
Copyright information: © 2020 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.